Cleaning Pet's Teeth

Today after work I dropped my two cats off at the vet's to have their teeth cleaned. I really hate this for multiple reasons, but the main one is how I feel about doing this to my cats. It's a very traumatic experience for them, and every time they (or humans) go under anesthesia there's a chance they won't wake up, even more so for older cats.

I haven't tried giving them anything to minimize the trips they need to make to get their teeth cleaned, but I'm going to start doing so very quickly. I know of treats that help, and I also know of an additive to their water that helps. The additive to their water is the easiest route, but I'm looking for the experiences of other pet owners here before I make a decision. What do you guys do?

I've got some packs of Orbit, but somehow I think I would have difficulty getting my cats to chew it. Even if they did, they'd probably just spit the chewed up pieces on the carpet or in a chair somewhere. Either that or they'd be walking around with balloons coming out of their butts.

Hills Prescription Diet T/D (i think) is one that is supposed to work well for teeth.
Nothing beats brushing but with cats that is no easy task. I recently lost a cat that had kidney failure related to bad dental problems. I've been much more aware of this stuff after that. Just like people, pets can really develop severe health problems due to dental issues.